Suicide bombing kills 3 in Afghanistan

The second such attack in four days signals Taliban's efforts to open a new front in volatile Kandahar. Separately, three policemen are killed in a friendly-fire incident as Vice President Joe Biden arrives for a visit.

Reporting from Kabul, Afghanistan — Insurgents Monday staged the second suicide bombing in four days in a strategic border district in southern Afghanistan, signaling determination to open a new front in the battle with coalition forces in volatile Kandahar province. Two policemen and a civilian were killed in the attack, for which the Taliban claimed responsibility.

Separately, Western military officials acknowledged that the NATO force had apparently killed three Afghan policemen in an airstrike a day earlier, in the year's first deadly instance of friendly fire. Afghan officials criticized a lack of coordination by Western troops.

The airstrike occurred in the same area — on the border between the provinces of Daikundi and Oruzgan — where a Western airstrike killed more than two dozen Afghan civilians almost a year ago after their vehicles were mistaken for an insurgent convoy.

The latest friendly-fire incident came as Vice President Joe Biden arrived in Afghanistan for a series of meetings to gauge the progress toward a drawdown of U.S. forces later this year and an eventual handoff of security responsibilities to the Afghans.

The unannounced visit was Biden's first since January 2009, when he was vice president-elect. During that trip he clashed sharply with Afghan President Hamid Karzai, with whom he will be meeting this week.

"This is a pivot point in our policy," a senior Obama administration official told reporters aboard Air Force 2 en route to Afghanistan. "We moved from a [troop] surge last year to the transition to Afghan lead that we'll be starting this year and concluding in 2014. So what he [Biden] wants to do in the first instance is to assess the progress we're making toward transition."

U.S. officials worry that corruption in Karzai's government is an obstacle to a stable, self-governing country that is not reliant on outside forces. And Karzai has his own complaints about his uneasy partnership with the U.S. Last week, he warned "our foreign friends" not to interfere in the internal affairs of his government, saying the Afghans don't want any "meddling."

The suicide attack in Kandahar province took place in the district of Spin Buldak, which borders Pakistan. Intelligence officials have warned that a Taliban group with suspected links to Al Qaeda has been operating from a base just across the frontier, in the Pakistani town of Chaman. NATO ground forces are not allowed to pursue the insurgents into Pakistani territory.

The Taliban group, thought to be led by Mullah Abdul Qayyum Zakir, is also believed to be responsible for a suicide bombing Friday in a public bathhouse in Spin Buldak. That blast killed 17 people, including a senior officer in the province's border police force. Zakir is a former Guantanamo Bay detainee who is now believed to play a senior role in the Quetta Shura, the Taliban leadership council based in the Pakistani city of that name.

Last year, U.S.-led forces largely drove Taliban fighters from three districts surrounding Kandahar city, which lies well to the north of the border. But the attacks in Spin Buldak, which had previously been relatively secure, suggest that insurgents intend to continue harrying Western and Afghan forces from across the frontier — even during the winter months, which traditionally bring a respite from fighting.

Months of relative calm in Spin Buldak had been widely attributed to former warlord Abdul Razzaq, who has allied himself with the Americans and serves as the commander of border police in Kandahar province. Monday's bomber apparently intended to target Abdul Razzaq's force, but the attacker's vehicle was spotted first by a contingent of national police, officials said.

Khan Mohammad Mujahid, chief of the national police in Kandahar province, said the assailant set off his explosives when police surrounded the car, killing two officers and a civilian nearby. The Interior Ministry, which oversees the Afghan police, provided a similar account, as did district officials in Spin Buldak.

The Taliban claim of responsibility, which came from Qari Yousef Ahmadi, the movement's spokesman in the south, derided the border police as a "puppet" force. Abdul Razzaq has been targeted by the Taliban in the past.

The friendly-fire killings of the three Afghan police officers, and the injuries of four others, occurred when they were mistaken for insurgents laying an ambush, the NATO force said in a statement. It expressed regret for the deaths.

Gen. Murtazaqul Dilshad, police chief in Daikundi, said police were working in concert with teams of Western special-operations forces at the time, and blamed a lack of coordination.

The strike took place not far from the scene of a U.S. airstrike last February, also called in by special-operations forces, which left at least 27 Afghan civilians dead. That incident triggered a public outcry and angry protests from Karzai.

In another development, the White House said Monday that the American official in charge of investigating corruption in U.S.-funded projects in Afghanistan had resigned. Retired Maj. Gen. Arnold Fields, an appointee of President George W. Bush, was praised in a White House statement for service as special inspector general for Afghan reconstruction. But many congressional Democrats in recent months had asked President Obama to replace Fields, saying he and his staff had been lax in rooting out corruption.